Dear Paul, There was a time when race relations in Britain could be symbolised by the very simple reference to there being "no black in the union jack". White people had the power, control, resources and the empire; black people were perceived as exotic immigrants doing the low-grade jobs and disfiguring the landscape as well as the labour and housing markets.

But no longer can a simple analysis be made of the state of race relations, as Britain's changed demography reflects new generations of multi-ethnic origins and heritage.

Over the decades different groups of people have had to assert themselves to get their grievances heard, sometimes engaging in uprisings. The last significant disturbances occurred in the northern English towns of Bradford, Burnley and Oldham in 2001. They highlighted resentment, hatred and ignorance, and the gulf between poor white and deprived Muslim communities.

This forced a redefinition of the race equality project, and faith, belief and religious identity are now regarded as issues warranting explicit consideration in all equality debates.

This has weakened some antiracist strategies. But now, with some of the anti-religious discrimination laws in place, with the proposed outlawing of incitement to religious hatred and with a new equality and human rights commission on the horizon, most people in those communities believe their concerns are, at least, being acknowledged.

However, there is now a whole new ball game: the terrorist atrocities of July 7 have created enormous uncertainties and deep fears across all communities and suspicions abound, despite the best efforts of the police and community and political leaders for calm and cooperation.Yours, Herman

Dear Herman, I do not agree that Muslim assertiveness is a primary source of our difficult new circumstances, or that the "race equality project" can, or should, be redefined in terms of faith.

To rely on outlawing incitement to religious hatred would be way off the mark. Surely that was just a convenient governmental gambit for separating "good" from "bad" Muslims, an ill-thought-out bit of diversity management judged to be a price worth paying in order to isolate the hotheads and agitators.

Bolting official religious sensitivity on to the apparatuses of "antiracism" only helps to reproduce exactly the sort of closed and stratified communities that might otherwise be withering away. Processes, identities and feelings that are fluid, complex and internally differentiated become fixed, naturalised and spiritualised. Re-describing cultural minorities more accurately will not be enough, in itself, to make Britain's official race equality strategies suddenly start to work better.

This is a different political game from the one played during the 1970s, but debate over the recent terrorist bombings has underlined many continuities with that period. It seems as though every asylum seeker is now a potential mass murderer. The old logic of expulsion/repatriation remains intact, and one of the bombers was even identified as a former mugger.

Blair's belligerent revival of empire and the occupation of "Muslim lands" are obvious factors, but another hatred seems to have festered in Beeston and other dead zones of England's postindustrial economy. Transposing these large cultural, political and economic problems into the language of faith and religion is a counterproductive oversimplification recycling the "clash of civilizations" idea.

The fantasy of Britain as a beleaguered country perpetually fighting Rourke's Drift against an invading horde must be explicitly opposed. We need leaders who will be brave enough to say not that we should stop apologising for the lost empire, but that it was the empire that made this country what it is, and that we are still dealing with the consequences.

We need to know what varieties of injury promote the absurd belief among young British people that an austere, political Islam can be a viable vehicle for their hopes for an improved world. But it is now unlikely that we will be able to explore those issues without inviting the accusation of sympathy with the perpetrators of mass murder.

It may be more important to ask what social, economic and cultural conditions can promote solidarity and mutuality across fluid cultural lines. Perhaps now might be a good time to see the struggle against ignorance as a civilising element that is also a means of building democracy and citizenship.Yours, Paul

Dear Paul, The media-generated fears of "invading" asylum seekers, gypsies desecrating the countryside, Muslims flexing their political muscle and international terrorists breaching our national defences make it even harder to achieve the much desired inclusive British identity.

Timidity and fear prevented our politicians from taking on the populist right, the tabloids, the Islamophobes and the Europhobes. In the eyes of our leaders there is a straight choice to be made by everyone. "Diversity, equality and integration" encourages and requires you to conform, compromise and comply in order to gain a level of acceptance. That is supposed to demonstrate successful management of ethnic relations as we see more and more non-white people penetrate the bowels of our institutions.

Two main actions are necessary to counter the bigotry, ignorance and misinformation that characterise race debates in Britain. The first is for political, corporate and community-based leaders to challenge all forms of misinformation and sensational media reports that demonise particular groups of people. This is more difficult to achieve in the present climate of real fear as well as paranoia.

The second concerns what should be happening in our places of learning. Parents are educating and influencing their children with their perceptions, attitudes and limited knowledge, so there is a huge gap to be filled by our nurseries, schools, colleges and universities.

Given that "antiracist education" is regarded in official quarters as unacceptable indoctrination ("political correctness"), how would you suggest that we might persuade our leaders and educationists to help build democracy and citizenship? Surely that is beyond our reach with the present levels of fear and vulnerability.Yours, Herman

Dear Herman,I applaud your frankness in saying that your associates in the Blair government are more scared of being called politically correct than they are of the consequences of demonising incomers and spreading fear.

If you are right, it is going to be impossible to persuade them of anything that might undermine their grip on power, which comes courtesy of mainstream floating voters in contested constituencies rather than from minority ethnic electorates.

It might help if we appreciate that the problems that derive from unacknowledged colonial crimes and unresolved imperial histories are not Britain's alone: similarly divisive issues exist in other post-imperial nations, from France to Japan.

The first things our leaders might gain from this shift are increased moral authority and political credibility, locally and beyond. Secondly - and here we can turn back towards the issue of Islam in Britain - political leaders might also gain loyalty and support from disenchanted and excluded people who might otherwise be tempted to dismiss all this chat about diversity and human rights.

The national solidarity you aspire to can only be built upon trust and an acknowledgement of the damage done by racism. Racism is a key source of the double standards in international affairs that feed local disenchantment and hopelessness.

This probably sounds like the dreaded "political correctness", but it is only racism that holds all British Muslims responsible for the wrongs perpetrated in the name of their faith by a tiny minority.Yours, Paul

Dear Paul,The disturbances of 2001 revealed the paucity of intermixture, interdependence and intercultural relations between groups inhabiting the same spaces in their local neighbourhoods. Later explorations showed that young white people and young Muslims in those areas were crying out for better teaching, more learning and the opportunities to mix with people different from them.

There is a large comprehensive school in the East End that has pupils from every conceivable impoverished background. Good communications between staff, pupils, parents and local communities as well as information-sharing and intercultural mixing combined with effective leadership give them self-esteem and confidence, and facilitate their respect for others. It works.

We need to see this replicated elsewhere and to rid ourselves of the notions that people must compromise, conform and comply in order to gain acceptance. We should not allow the terrorism crisis, with its evil ideology and global influences, to blow off course the progress we have made.Yours, Herman

Dear Herman, You sound as though you are groping your way back towards a class-based politics. Of course, the intercultural contacts I am interested in are not evenly spread across the whole country: London may be the world, but it is not all of Britain.

My point is that these changes need to be recognised and accorded political significance. Let us agree that we need a map of Britain's new political and cultural geography. The 2001 riots took place before the US-led "war on terror".

Residential segregation and postindustrial economic resentment were not their only triggers. On one side, there were the old conflicts: with police, with the BNP and with the white working class in the labour market. On the other, there seems to have been a new kind of antagonism based on envying the identity, cohesion and solidarity of the post-migrancy generations.

Excluded whites may even have experienced an "identity deficit", as well as a shock, when they discovered that whiteness has lost its prestige and is now worth next to nothing. That is when they become susceptible to the idea that there is a clash of civilisations going on with a long frontline that runs from Burnley to Basra. Yours, Paul

Dear Paul,We can certainly agree on the need for a map of Britain's new political and cultural geography. I also cannot disagree with your analysis about triggers for conflicts.

If I am groping for anything it is to hang on to those fundamental things that work for disadvantaged communities, including demonised communities such as Muslims and asylum seekers, while we await the emergence of the political leadership with the necessary bottle to challenge the status quo. I am encouraged enormously by the community and political leadership in the present circumstances. Out of such adversity often emerges real benefit, and that would be a special legacy in memory of all those who have been the victims of evil and hate. Yours, Herman

Dear Herman, These are very dangerous times. The British history, which our generation helped reshape, now offers valuable lessons about how to get along convivially in a multicultural polity. The shrine at King's Cross and the crowd at Stockwell station conveyed this vividly.

I know you do not want to wait for our leaders to find the courage to act. Perhaps we need an infusion of courage, too. In the meantime, Britain's jails are brimful of Reids and Moussaouis. A few young people from all backgrounds will respond to the siren call of political Islam because it offers them an ascetic and strongly ethical response to the erotic dazzle of consumer culture from which they are excluded, and exclude themselves.

What healthier, secular alternatives can we offer them? Fundamentalism's over-simple solutions harness the disenchantment that grows with marginalisation and hopelessness. There must be more to British citizenship than bullying asylum seekers to get their grammar right and swot up on their kings and queens.

Education is fundamental. Another key is cultivating a political outlook that does not counterpose solidarity and diversity so that more of one means less of the other. That, for me, was one positive aspect of wounded London's response to the recent outrages. Can that spirit - which is not the resilience of the blitz and the flipside of hating Germans - now take root outside London? Yours ever, Paul

· Paul Gilroy is Anthony Giddens professor of social theory at the London School of Economics and author of After Empire: Melancholia or Convivial Culture; Herman Ouseley is former chair of the Commission for Racial Equality and author of the Community Pride Not Prejudice report into race relations in Bradford in 2001.

· A version of this discussion appears in Islam, Race and Being British, edited by Madeleine Bunting. To order your free copy, plus postage, send a cheque made payable to the Guardian for £2.50 to Guardian Branded Books, 119 Farringdon Road, London EC1A 3ER.